


Could we knot

by Biru



Category: Yu-Gi-Oh! Duel Monsters (Anime & Manga)
Genre: Alpha - Freeform, Alpha/Beta/Omega Dynamics, Alpha/Omega, Anal Sex, Knotting, Loss of Virginity, M/M, Mating Cycles/In Heat, Porn With Plot, Virginity, beta, omega - Freeform
Language: English
Status: In-Progress
Published: 2020-04-10
Updated: 2020-04-19
Packaged: 2021-03-01 16:40:42
Rating: Explicit
Warnings: Underage
Chapters: 4
Words: 13,416
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/23580214
Author URL: https://archiveofourown.org/users/Biru/pseuds/Biru
Summary: After Jounouchi Katsuya's embarrassing defeat at the hands of Kaiba Seto's on Duelist Kingdom, Kaiba leaves to find Pegasus. Not being done with Kaiba yet, Jounouchi follows the rich bastard into the woods, where Kaiba unexpectedly presents as an omega as he goes into heat for the first time.This spurs on a begrudging alpha omega relationship between the two.
Relationships: Jounouchi Katsuya | Joey Wheeler/Kaiba Seto
Comments: 40
Kudos: 90





	1. Presenting as an omega

**Author's Note:**

> Hello there!
> 
> This is my first fic in a long time, and my very first fic with alpha/omega dynamics. I'm intending this story to span over the entire yu-gi-oh timeline up until the series finale!
> 
> I've added the tag underaged as both Kaiba and Jounouchi are canonically 16 years at this point. It might not be underage in Japan or some other parts of the world, but you can never be too safe. 
> 
> Well, basically this is gonna be porn with some plot. But mostly porn. Hope you enjoy!

**Notes for the Chapter:**

> Edited some phrases and sentences in the first chapter so the writing is less awkward

It was the middle of the night on Duelist Kingdom when Katsuya Jounouchi was sleeping on the forest floor before being startled awake by the sound of an obnoxiously loud helicopter. The helicopter landed in the vicinity of the Mutou Yuugi group. A person stepped out of the vehicle which turned out to be Kaiba Seto. Well, of course.

Jounouchi quickly realized that he couldn’t stand the other boy. It was both the obnoxious entrance with the helicopter, his disregard of the rules on Duelist Kingdom with the star chips, and his overall arrogant attitude. Most of all it was that  Kaiba seemed to be above it all, not giving a damn; it insulted  Jounouchi’s alpha pride sensibilities. It didn’t take long before aggravating  Jounouchi to the point of grabbing  Kaiba by the front of his shirt, threatening him with… something.  Jounouchi didn’t know, violence, a duel?  Jounouchi wasn’t one to be in the habit of thinking that far. And he didn’t get to before  Kaiba had grabbed his hand and thrown him face first to the ground. In hindsight, it was extremely humiliating.

It ended with a duel, of course, after some back and forth retorts to one another. They dueled with a completely new technology, the Duel Disk System, which  Kaiba produced from a suitcase. A technology that  Jounouchi thought was endlessly cool, though he would never admit it out loud. 

Jounouchi lost the duel spectacularly; never even posing a threat to  Kaiba . He fell to his hands and knees as  Kaiba mocked and insulted him, as was his bragging rights as the winner. With the newly found shame and humiliation Jounouchi stayed down a took it without a word, finding it difficult argue back, even as his friends defended him.  Kaiba and  Yuugi talked about something that  Jounouchi failed to listen to in his post-losing trance. 

Then  Kaiba left, disappearing in-between the trees. After a short while  Jounouchi snapped out of his trance, fueled with a new surge of anger and darted after  Kaiba through the woods in the dead of night, ignoring his friends’ calls.

“Where are you, moneybags?”  Jounouchi called while running through the trees.  Kaiba was nowhere in sight, and it would be difficult to spot him as the moon barely illuminated the forest around him, though  Jounouchi didn’t give up. He kept running through the woods in pursuit, the calls of his friends becoming more and more muted until they died out completely. He ran for a while without direction, zigzagging through the woods. Somewhere back in his mind he wasn’t at all optimistic that he would find Kaiba. “Show yourself!” he tried calling again.

Jounouchi stopped to a halt catching his breath, hands on the knees. In the distance ahead he heard a faint ‘crack’ like someone had stepped on a dry branch. “Gotcha!”. He ran as quietly through the woods as he could, trying his best to not tread on dry branches himself. Not before long  Jounouchi spotted  Kaibas trench coat which appeared dark grey in the darkness. Jounouchi smirked. 

“Hey, Kaiba!” He yelled, catching up to his target.

Kaiba turned around, facing the approaching boy. “What do you want, mutt? Want another embarrassing defeat? As if the first one wasn’t bad enough for you.”

Jounouchi made a growl from way down his throat “I’ll show  _ you _ , Kaiba!”

Kaiba, in turn, gave a mocking laugh “Show me what, exactly?”. He stopped smiling and shot him a dead serious look. “You’ll never be a proper duelist.”

That put  Jounouchi over the edge. He clenched his fist and threw a punch to the other boy’s face, though  Kaiba caught it easily.  Kaiba’s gave him a condescending laugh, as he twisted  Jounouchi’s hand. “You’ll just never learn, will you?” And with that Kaiba threw  Jounouchi to the ground, not unlike the first time. “Stop wasting my time, loser.”

On the forest floor once again,  Jounouchi gave a low growl that came from deep down his throat. He looked over the shoulder at  Kaiba , who was walking away calmly, which only aggravated him further. “Not so fast, moneybags”  Jounouchi ground out, as he got up and charged at  Kaiba .  Jounouchi tackled the other with a full-on body slam to the back that sent them both to the ground, flinging the suitcase into some nearby bushes. 

“How dare you, you deadbeat-” 

That was all  Kaiba could ground out before  Jounouchi was on top of him, wrestling him. They fought in the grass and dirt, trading curses and insults at each other. In the end  Kaiba ended up on top, holding  Jounouchi down by grabbing the front of his jacket and straddling him. Both boys were breathing heavily.

“What  _ exactly _ did you think you would get out of this?”  Kaiba growled, giving  Jounouchi a hard shove into the ground. Then he suddenly went still.

“Aww, c’mon. Don’t be like that sweetheart.”  Jounouchi expected a retort or a fist in the face, but nothing came. Weird. He grabbed  Kaiba’s hands to try to pry them off. “Hey! Get off of me  Kaiba or I’ll-” but then the smell hit him. 

For several moments both of them were frozen in place.  Kaiba had a shocked expression on his face with eyes wide and mouth slightly open.  Jounouchi sported a similar expression.  Kaiba smelled sour and sweet at the same time, an utterly enticing smell that completely overwhelmed  Jounouchi’s senses.  _ That smells incredible _ . 

“I didn’t know you were an omega”  Jounouchi said bewildered making no effort to move.

They stayed like that for a couple of seconds. “This can’t be happening. This isn’t happening”  Kaiba said with a small, fear-stricken voice.  Kaiba let go of the other boy and attempted to rise, but  Jounouchi held on to his hands. “Let go of me,  _ mutt _ ” it was obvious that  Kaiba tried to sound demanding, but the words came out as a desperate plea. He looked utterly confused and petrified with his pupils abnormally enlarged, like an animal. 

“It can’t be that it’s your  uhh -”  Joucnouchi licked his lips, trying very hard to breathe through his mouth, but the smell of an omega in heat was impossible to escape when the subject in question was literally on top of him. A voice in the back of  Jounouchi’s head said that he should let go, and stay away from  Kaiba before things escalated further. But a stronger and more primal voice inside him called a lot louder. “Is this your first heat?”

_____

The sudden arousal felt a punch in the gut. All at once he felt dizzy, light-headed, his cheeks were burning up and cold sweat ran down his back. The feeling was so sudden and intense that he froze in place, shocked. From one moment to the next,  Seto had seemingly run head first into a brick-wall of sexual desire; an unfamiliar physical urge unlike one he had ever experienced before. That was when he noticed a disgusting wet and slick feeling between his legs.

It didn’t register in his brain what was happening to him until he heard the other ask “I didn’t know you were an omega”

An omega?  Seto was positively mortified. He had always believed that he would either present as an alpha or at least a beta, as he’d always had the characteristic traits from former; aggressiveness, competitive, self-assured, and on some deeper level he also knew that he was quite arrogant. It never crossed his mind that he would actually present as an omega. And of all of the times he could have presented as an omega, his biology chose this very moment to do so. 

Talk about bad timing. 

Seto had much more pressing matters at the moment. His position at  Kaiba Corp was threatened, and  Mokuba was imprisoned by Pegasus; the very man who’s currently attempting to stage a coup d’état. 

And Seto was alone in the woods. With Jounouchi. Who was unmistakably an alpha. Seto couldn’t help being painfully aware of this fact. It became obvious the moment that Jounouchi had the opportunity to give a good whiff at Seto, at which Jounouchi himself produced a thick aroma of alpha musk. Seto had never actually smelled an alpha in a rut, but he’d had enough sex education to know that was exactly what this was. 

Seto was an omega in heat.  Jounouchi was an alpha in a rut.

“This can’t be happening. This isn’t happening.” A chill crept down his spine as he let it sink in. He gathered enough wits about him to realize that being in this close proximity to  Jounouchi was a really bad idea.  Seto tried to rise, but  Jounouchi grabbed a hold of him. 

“Let go of me,  _ mutt _ ” but  Jounouchi didn’t let go.

“It can’t be that it’s your  uhh … Is this your first heat?”  Jounouchi asked with a stupid expression on his face, still holding on to Seto. 

Seto didn’t dignify that with an answer. Instead he gathered enough strength to forcibly wrestle free and scramble to his legs. He wanted to flee the scene, but his legs felt like lead, and he couldn’t ignore his increasing arousal. This isn’t good.

“It is, isn’t it?”  Jounouchi rose up, standing too close to Seto. 

Seto wanted to give a snarky retort, but the words were stuck in his mouth. In the meantime,  Jounouchi leaned in, nose to the crook of  Seto’s neck, and inhaled deeply. The smell of alpha and rut became that much stronger, and  Seto could only stand still as the scent washed over him as a thick blanket and filled his thoughts and senses. 

A sliver of rational thought told him that he should run and deal with his first heat in solitude, and that this could end very badly. But being a 16-year old boy with too many hormones, his rational thoughts were quickly drowned out with more urgent matters. Smelling the rut only made  Seto’s own desires stronger, and suddenly all feelings of fear and confusion were washed away. And  Seto could only think of one thing.

_ Sex _

Seto once again grabbed  Jounouchi’s jacket with both hands and pulled him in to an aggressive, sloppy kiss.  Jounouchi didn’t protest at all, rather he flung his arms around  Seto , one hand in his hair and the other around his waist. The blond boy took the opportunity to explore the inside of his mouth, and  Seto let him. The aggressive kissing session quickly turned into heavy petting as both  Jounouchi’s hands were feeling up  Seto’s backside before moving on to his erection instead.  Jounouchi was the one to take off both of their outer wear, still with mouths still interlocked, only parting briefly to breathe at times.  Jounouchi moved on from the mouth to kiss  Seto on the corner of his mouth to his jaw to his neck.  Seto just leaned his head back, hands on  Jounouchi’s shoulders, and let the other boy kiss and feel him up.

Everything happened quickly.  Seto couldn’t recall when they undressed, but suddenly both boys were completely nude. With hands on  Seto’s shoulders,  Jounouchi effectively directed him to lay on his back on the grass. 

It vaguely occurred to  Seto , that he was being passive in all of this, submitting to the alpha’s will. It was never in his nature to be passive in anything, and having someone else take charge, especially the likes of  Jounouchi . But right now he depended on an alpha to take charge, depended on someone guide him as he experienced feelings and urges he had never felt before.  Seto knew he would resent himself in the morning, but in the moment, he just couldn’t seem to care.

Seto was now laying on his back while  Jounouchi gave him another sloppy kiss before moving further down with wet and loud kisses as he ran his tongue over the other boy’s neck, chest, stomach. Further and further down he went, until he came to  Seto’s fully erect member that was already leaking precum.  Seto’s breath hitched as  Jounouchi gave it an experimental lick before he went further down to the hole.

For a moment everything went still.  Seto laid there breathing heavily while looking up into the skies. He refused to look down, but he could feel that  Jounouchi was staring at his entrance, which he was aware of was leaking an embarrassing amount of slick.  Seto was never shy about his body per se, but being aware of the other boy’s intense staring of his private parts, even in the relative dark, was utterly humiliating.

“What are you doing? Get on with it.”  Seto managed to growl in a low, needy voice. 

“Huh?”  Jounouchi sounded like he was startled awake from a trance. “Oh, sorry...” 

And just like that,  Seto felt  Jounouchis nose touch his entrance and heard him take a deep, audible breath. Having both hands at his sides, gripping the grass,  Seto gasped and arched his back at the sensation of the other touching him there. 

“That smells good”  Jounouchi sounded completely gone in his arousal.

And just to further  Seto’s embarrassment, he felt himself produce another wave of slick at  Jounouchi’s praise.  Seto was damned if he would ever admit it out loud, but he was so close to begging. Everything in his mind screamed at him, that he needed to be filled up, that he needed an alpha  _ right now _ .

Not before long  Jounouchi had gripped  Seto below his knees, raising up his legs. The blonde boy hastily lined up his own member to  Seto’s entrance. The sensation made  Seto think  _ yes, yes, yes!  _ And without further warning,  Jounouchi entered.

Seto moaned, loud and lewdly as he had never done before, sounds that he didn’t even know that he would produce. The feel of  Jounouchi inside him felt hot and burned in the most delicious way.  Jounouchi gave him no time to adjust, before he pounded away with all urgency and without restraint. With every other pound  Jounouchi made a small grunting noise. He now had his hands on Seto’s hips, gripping them so hard that there would probably be bruises in the morning. Sex was both painful and pleasurable and ‘ _ oh’ _ if that wasn’t the best feeling in the world.

Their fast and hard mating made loud and wet sounds in the night. _Squelch, squelch, squelch. Slap, slap, slap._ Seto would probably think it embarrassing later, together with many other things, but right now his mind was completely blank, leaving him to be in the moment.

In the heat of it,  Jounouchi mouth went to the place where  Seto’s neck met the shoulder and bit down.

“Ahh~” Was all  Seto could say, not at all registering what Jounouchi was doing.

Then  Jounouchi grabbed  Seto’s shoulders and began pressing him down on something on the base of  Jounouchi’s member. Seto had completely forgotten about the knot.

“Ah, yess, please~ ” Seto heard himself whine as Jounouchi begin pressing the knot in. “Please, _moore_...” It didn’t even sound like his own voice in his ears, like someone else were using his mouth to say these words that Seto would never say out of his own volition. But here he was, begging like a bitch in heat for an alpha’s knot.

And then the knot went in. 

And it hurt like fucking hell!

_____

The orgasm rippled through him in waves the moment the knot went in.  Jounouchi slowly came back to his senses as the orgasm ended, as if he had been in a drunken daze. Or rather, a rut-induced daze. It wasn’t that he couldn’t remember what had just happened, because he could. It all just felt like a surreal dream. Him having sudden, primal, and completely satisfying sex with  Kaiba . It was as  Jounouchi came back to himself that he noticed the other boy.

“ Nrrghh ”  Kaiba’s eyes were closed and his face was scrunched up in pain. He put a fist in his mouth to try to not make a sound. If Jounouchi wasn’t mistaken,  Kaiba were moist around the eyes.

“Hey, are you alright?”

“Hrmph” Was the only response he got.

Jounouchi looked down at where they were joined together. “Oh, right... The knot.”

They laid there on the forest floor for some time without speaking.  Kaiba with his eyes closed and hand in mouth, and  Jounouchi tried to look everywhere else, as he could do nothing else while they were stuck together.  Kaiba breathed heavily through his nose, seemingly battling hard against making any sound and crying. 

_ Oh no, what have we done? I came inside him without any protection... Shit. What if he-? Shit... I should never have followed him. _

After a while  Kaiba’s breath became steadier and he removed the hand.

“How long are we going to be stuck together like this?”  Kaiba didn’t sound angry, as  Jounouchi would have expected him to be, but rather just tired and a little defeated.

“ Uhmm .. Whenever I masturbate, my knots last somewhere between 20 to 30 minutes.”

“Uuurghh”

“I’m usually pretty proud about that, but right now I wish... You know.”

…

“How much time has passed?”  Kaiba asked.

“I  dunno . Maybe five minutes?”

Kaiba let out a small sound that could sound like a mewl.  Jounouchi bet with himself that  Kaiba didn’t make that sound voluntarily, as the prick seemed like a proud person, being pretty arrogant and all.  Kaiba looked quite miserable right now, and  Jounouchi felt a little sorry for him. Neither of them looked at each other.

Some time passed, and the knot didn’t seem to want to deflate any time soon. A thought sprang to mind.

“What are we  gonna do if you, you know. Get pregnant?”

Kaiba jolted slightly at the question. After a while he answered “I don’t want to think about that.”

Fair enough. 

Some more time passed, and  Kaiba began to make small whimpering noises.

“Does it hurt?”

“What do  _ you _ think, moron.” Kaiba wasn’t quite crying, but more moisture was trapped around his eyes.

“... I thought that knotting was supposed to feel good for the omega”

“It’s my first-…. And there should be more preparation involved.”

“Oh, right...”

“...”

“This is my first time too.”  Kaiba didn’t answer. “A lot of the others at school always thought that I lost my virginity a long time ago. Because I was a delinquent and all, you know? But I haven’t. You’re my first”

“Why are you talking to me?”

“Just trying to get your mind off things.”

“...”

“...”

“You’re still a loser.”

___

Time passed, and the knot finally deflated, releasing both boys. As  Jounouchi slid out of  Seto , he could feel more slick fluid and what he was sure was  Jounouchi’s semen exit his body.  Seto hid his face with his hands with a low “ Uurgh ”. Between his legs he could feel the disgusting crust of dried fluids sticking to his inner thighs and newer fluids sliding down his cheeks. This, however, didn’t distract from the fact that he still felt a painful ache from where he had been knotted. He was going to feel that tomorrow. And the day after that. And probably the day after that.

Jounouchi arose first, followed shortly by  Seto . Both boys looked at each other with apprehension, unsure of how to proceed. Both boys redressed in complete silence, not looking at each other.  Seto found his suitcase that was flung into some bushes earlier. When both were done, they faced each other in silent acknowledgement. 

“ Erhhmm .”  Jounouchi said with a hand on the back of his head. He looked stupid as ever,  Seto thought.

“I would appreciate it if we kept this between ourselves.”  Seto said with an even tone. He found that all of the fight and aggressiveness from earlier had left him long ago. 

“Uh, of course.”  Jounouchi looked at him thoughtfully. “I know that you said that you didn’t want to think about it... But what if you  _ are  _ pregnant.”

Seto’s first instinct was to give a sarcastic retort, but he stopped himself. It wasn’t an unfair question after all. “I’ll go to the doctor when I’m done with Pegasus. If I’m... I’ll let you know. We’ll take it from there if that’s the case.”

Jounouchi nodded. “Alright.”

“Nothing happened here tonight.”

“Nothing happened”  Jounouchi agreed.

And with that, both boys gave each other a final look and went their separate ways.


	2. Complications

**Summary for the Chapter:**

> Kaiba has been to the doctor

“Yeah, it’s me!” Jounouchi said with a cheery voice as he picked up the phone. 

“We need to talk.” 

Jounouchi didn’t answer, trying to place the voice on the other end. 

“I’ve been to the doctor.” 

“... Oh no. Is this because... Are you-?” 

“No. It’s not _that_ ” Kaiba answered hastily. “We still need to talk. I’ve sent a car for you.” 

“Oh. Ok then?” 

_Click._

___   


It had been a bit over a week since Seto’s rather rough first-time mating in the woods. Since then quite a lot had happened. Seto had gotten his brother back, Pegasus wasn’t a problem anymore, and he was no longer at risk at losing Kaiba Corp. The men behind the attempted coup d’état had been fired, and it was unlikely that they would find similar positions at other firms with their actions being outed and their names being tarnished forever in the professional world. 

On that front all was right with the world. Though in the dueling world it was not so, as Mutou Yuugi had become king of games at Duelist Kingdom. Yuugi being the one to bring down Pegasus. And not Seto. That did not sit well with him. He needed a rematch that would prove once and for all that Kaiba Seto was the superior duelist and the rightful king of games. 

Then there was the last thing. Seto had presented as an omega and promptly lost his virginity. Seto had predicted that his backside would ache after that experience, and begrudgingly, he was right. He had inwardly winced for two days afterwards every time he either sat down or got up again. As it turned out, Jounouchi had ripped him a little, as Seto found blood by his hindquarters when he cleaned himself up after the encounter. It wasn’t a dramatic rip though, and no further complications arose as it healed again within the hour. 

After he and Jounouchi had parted ways, Seto had bumped into him and his friends a couple of times. First by Pegasus’ castle, where Seto dueled Yuugi, and again after Seto had regained his soul and given Yuugi and gang a ride home. Seto lost his soul. Huh. That was unexpected. During these encounters not even a brief acknowledgment passed between the him and Jounouchi, honoring their agreement. 

It had been surprisingly easy to ignore the ‘incident’. 

Soon after Seto had returned home with Mokuba and re-established himself within Kaiba Corp, he had gone to the doctor to get checked. 

Seto had found the entire ordeal quite humiliating, if not more so than the mating itself. He had had an embarrassing talk with the doctor, where he had to explain his new status as an omega, the circumstances of his first heat, and sudden loss of virginity as a result thereof. Following the talk, he had to get his urine tested, and he underwent a rather invasive pelvic exam. 

No serious consequences had occurred after the mating. No physical damage, he hadn’t contracted any sexually transmitted diseases... and he hadn’t conceived. Thank god. 

Though there was one detail, that might pose a problem in the future. 

“Did the alpha bite you? Or did you bite him? I’m assuming that it’s a him, of course” the doctor asked. He was a small, middle-aged man with big glasses and a mustache. 

Seto thought about the question. He honestly hadn’t noticed anything of the sort during the mating, and he hadn’t given it any thought afterwards. To be fair, there was a lot going on. He had been more aware of the ache to his backside, and his mind had been on this brother and Pegasus. Now that the doctor was asking, he subconsciously put a hand to his shoulder. 

“Perhaps. I don’t remember every detail.” 

“Take off your jacket and shirt, please” 

Kaiba did as he was told, now letting the little man examine his neck and shoulder area. 

“Ah yes. This is definitely a mating bite. You can put on your clothes again.” 

“Is this going to be a problem?” Seto asked, as he dressed. 

“Well-” 

“Well _what_ , exactly?” Seto snapped, now on edge. 

“Well you see, this could complicate your next couple of heats.” 

“What?” Seto suddenly felt extremely annoyed at the doctor. 

“You see, it is usually not a problem for a mated omega to break up with the alpha and move on. There’s of course a period of time ranging from five days to two weeks where the omega is in a hormonal imbalance after the first heat followed by the break up. Symptoms of this imbalance being fatigue, nausea, and the general feeling of being unwell, among other things. The severity of the symptoms of course varies from person to person. The chances for complications are almost always slim to almost non-existent.” 

“But?” 

“But you were mated during your first heat, and you’re also sixteen to boot. I have to emphasize that that is a very delicate time in every teenager’s life hormonal wise, whether he or she being an alpha, beta, and in your case; an omega.” 

During the doctor’s explanation Seto felt his stomach doing a mild somersault. He listened intensely and waited for what, he was certain, was very bad news. He tried very hard to not let his growing discomfort show in his features or body language, but as the doctor went on, it grew increasingly difficult. “Go on” he said with the faintest tremble in his voice. 

“I’m sorry to say that you have a higher risk of developing complications if you do not continue mating with this specific alpha during your next couple of heats for at least a year.” 

And there it was. It was like being doused with a bucket of cold water. Seto felt light-headed as he had during the first heat, and his hands went cold and felt prickly, as if being stung by a thousand needles. “What complications are we talking about?” 

“There is a chance that the hormonal imbalances won’t disappear for the rest of your life. There is a thirty percent chance of this happening. Hmm. It may not sound that dramatic, but chronic fatigue and nausea, and other symptoms, could decrease your quality of life overall. I’m urging you to take this seriously.” 

“...” 

“We should talk about contraceptives.” 

___ 

“Thirty percent?” Jounouchi repeated dumbly. He had been confused as to why Kaiba would want to talk to him, especially since the rich bastard had told him that he was not carrying. Jounouchi had been able to push back those fears during Duelist Kingdom, but after returning home and daily life went back to normal, Jounouchi would be lying if he said that he wasn’t lying awake at night thinking about it. Now he couldn’t help to relax his shoulders in relief, and a knot in his stomach disappeared. 

At the moment both boys were in what Jounouchi assumed was Kaiba’s office in that ridiculously tall Kaiba Corp building. It was a nice view over the city though. 

“Yes, thirty percent chance. So, are you going to do it?” Kaiba asked. He seemed way too calm about asking this. 

“Uhh. Do it?” 

“Are you just going to repeat everything I say, dimwit? Even _I_ thought you had more intelligence than this. I suppose that was my mistake.” 

“HEY! This is a lot to take in, you know!” And just like that Kaiba had him riled up, making Jounouchi shake an angry fist at him. 

“Do I have to call security?” Kaiba retorted, completely calm. 

“Grrr, you sure have a funny way to ask for a favor.” 

For several moments both of them just stared each other down. Kaiba had an infuriatingly relaxed and confident expression on his face, while Jounouchi visibly scowled. Despite the absurdity of the situation, Kaiba still acted like he had the upper hand, and he even had the audacity to act like _he_ was doing _Jounouchi_ a favor. 

Jounouchi seriously considered turning down the proposition. And just as he was about to open his mouth and tell Kaiba to ‘fuck off’ a thought occurred to him. 

_I could have free booty calls every couple of months for at least a year... But it’s_ _Kaiba_ _. But he’s offering sex. But it’s still_ _Kaiba_ _. But if I don’t, he might get those complications, or whatever. But it’s_ _Kaiba_ _._

Jounouchi took his time thinking it over, making all kinds of expressions as his thoughts went back and forth over the dilemma that Kaiba had presented. Meanwhile Kaiba looked utterly unimpressed as he waited for an answer. 

_He’s asking me to knot him._

“Alright. I’ll do it.” 

“Fine” Kaiba said with a pointed tone, crossing his arms. 

“So, uhh. When is the next time we’ll see each other again?” 

Kaiba sighed deeply. “Normally an omega goes through four cycles a year, which means they go into heat every three months. But as the doctor told me, the second and third heat can be unpredictable after presenting the first time. It could be tomorrow, or in three months.” 

“Ok then.” 

“I’ll send a car for you when it’s time.” 

___ 

Turns out Seto’s second heat came two weeks after his talk with Jounouchi. He had hoped that it would take at least a month before he had to deal with another heat, but no such luck. He was in the middle of a business meeting, when he was suddenly attacked with intrusive thoughts of one of his alpha business associates having sex with him on the table. That was when he figured he was probably going into heat. 

He excused himself with feeling unwell, and it didn’t seem like anyone at the table seemed to catch on to the real, underlying reason. He was on his way home when he had called for a car to pick up Jounouchi. No one, not even Mokuba, knew he was an omega, save for the doctor and a few trusted servants that he knew would keep his secret. Seto knew that he couldn’t keep his presentation hidden forever, though he would reveal himself in time. 

His second heat was very different from the first. During his presentation, the heat had been sudden and violent, like someone had turned on a switch, and it had consumed him completely. This time the heat started out quite mild, much like it was supposed to be, as he recalled the sex education lessons. A heat would normally last twenty-four to forty-eight hours, starting with a slow build that would get increasingly more intense until reaching a peak point, after which it would slowly die down again. Though a heat was usually gone after the twenty-four hours if an omega was mated by an alpha during it, and could possibly stretch to forty-eight hours if the omega was left alone. 

Seto was thankful for the initially mild heat, as it allowed him time to return home to the Kaiba mansion and prepare. The thought gave him a slight shudder. 

Seto was calmly waiting in his bedroom, when Jounouchi entered. 

“Knock knock!” Jounouchi said with a nervous grin. 

“Hrmph.” 

Jounouchi closed the door behind him before facing Seto. For a while neither said anything. There is probably going to be a lot more silent staring at each other in the future, Seto thought. 

“Soo, you’re in heat?” 

“What gave it away, brainiac?” 

Jounouchi didn’t answer as Seto would have expected him to. Instead he just stood there, visibly nervous. Seto himself had felt quite calm until now, but now that the other boy stood in front of him, being called here for one reason only, Seto felt his resolve crumble. 

He suddenly felt a feeling he never feels. Shy. 

Last time both he and Jounouchi had been gripped by the sudden, intense heat, wiping away all thoughts and apprehension. This time they both stood there, with their rationales still intact. This was going to be a lot more difficult than Seto had initially anticipated. 

Jounouchi moved forward, at which Seto was almost startled. Almost. The blond boy gave him a sniff. 

“Well, it’s not as strong as last time.” 

“...” 

Jounouchi brought a hand behind his head and scratched. “Should we maybe wait? You know, until the heat gets stronger?” 

“I would have wanted that too, but no.” 

“Huh? Why not?” 

“If I have to spell it out for you, which I’m guessing I have to-” 

“Hey!” 

“I need to be prepared, otherwise it’ll hurt like last time we... _knotted_.” Seto couldn’t quite keep the contempt out of his voice. “We need to do this now, so that we’re able to take it slow.” 

“Oh right, of course.” 

A blush crept over Jounouchi’s face, and Seto cringed inwardly as he felt his own face heating up. They once again stood in awkward silence, both unsure of how to proceed from here. 

“Should we maybe kiss?” 

“Absolutely not.” 

“Riight... We kissed last time, though” 

“I don’t remember that.” 

“Of course you don’t.” 

After a round of more staring, Jounouchi began to take off his clothes without a word. With slightly trembling hands, Seto followed suit. Too soon they were both undressed, now only wearing underwear. Seto was thankful for this, as he was not quite ready to be completely nude before Jounouchi. 

Seto usually felt older beyond his years, like an adult trapped in a sixteen-year old's body. But right now, he felt his age. Like a nervous teenager who was about to have sex for the first time. His actual first time notwithstanding. And he actually felt a little excited at the prospect! He _really_ hoped that it was the heat talking. 

While he had undressed, Seto had felt that disgusting feeling of slick escaping his backside. Disturbingly, more intrusive thoughts had invaded his mind as he imagined Jounouchi mating him in all kinds of positions. Seto _really, really_ hoped, that it was just the heat warping his mind. 

Seto had been half-hard almost ever since he discovered he was in heat, but while undressing he was sporting a full-on boner. So was Jounouchi, when Seto glanced down at the other boy. His pupils were also slightly more dilated than normal. It was quite off-putting, if Seto was honest with himself. Though, he supposed his own pupils looked pretty similar at this point. 

“Let’s get on with it” Seto said, as he walked over to the bed, expecting the other boy to follow. 

Jounouchi snorted. “Quite the romantic, aren’t you?” 

Seto would never admit it out loud, but right now he was grateful for the blond boy to keep the situation somewhat light. 

___ 

They were now both sitting on Kaiba’s bed. In his giant, opulent bedroom in his giant, opulent mansion. Jounouchi would never have anticipated ever being here. And now he was on Kaiba’s bed, almost naked. 

“Ok rich boy, what do we do first?” 

“Don’t call me that.” Kaiba retorted immediately. “And we should start with some preparation” 

“Ok...?” 

Kaiba actually had the decency to blush. _Aww, isn’t that cute?_ Jounouchi mocked on the inside. Believe or not, but Jounouchi was kind enough to not ridicule Kaiba right now, as Jounouchi figured, that he had never been this vulnerable in his entire life. He still thought that Kaiba was a rich, arrogant son of a bitch, though. 

“Start with your fingers...” Jounouchi winced a little, it actually looked like it physically hurt Kaiba to say that out loud. 

“Ok. Uh. You should probably take those off” Jounouchi said, gesturing to Kaiba’s briefs. 

“... Yes” 

Kaiba pulled himself to lie flat on his back in the middle of the bed. With hesitant fingers he took of the remaining underwear. He was now completely naked. Jounouchi swallowed a big lump in his throat, and hoped that Kaiba didn’t hear it. 

“Alright, let me try to take it from here.” 

Jounouchi tentatively moved so he was between Kaiba’s legs, crouching over the other boy. Kaiba turned his head and looked at no particular spot on the wall. He raised up his legs in a mechanical motion to let Jounouchi have better access. 

Jounouchi felt his mouth salivate at the sight. Just like the first time, he was completely enamored with the wet, pink hole. His own member leaked precum now. He mentally slapped himself to try to force himself not to stare for too long. 

He took a deep breath, and inhaled, the air was now a little thicker with the scent of an omega. He put in his middle finger and heard Kaiba take a deep, audible breath at the intrusion. 

It was surprisingly tight, despite the fact that he had been able to fit in his entire knot in there the first time. He moved his finger in and out and hoped he was doing it right. The hole was all slippery and wet, and it made Jounouchi salivate even more. Kaiba didn’t say anything, still looking at the wall. That was fine, he thought, he didn’t actually want them to look at one another during this. Before long he added a second and third finger. 

“Kaiba... Can I? Please?” 

Kaiba looked him briefly in the eyes before answering. “Yes” 

Unable to keep in his excitement he ripped off his remaining underwear and lined himself up, his whole body trembled violently with lust now. Kaiba’s legs were now wrapped around his waist, and his hands were placed on his upper arms. 

“Be careful when you enter.” Was that a hint of nervousness in Kaiba’s voice? “Just, be gentle.” 

“Ok” 

And with all of the remaining self-restraint Jounouchi had, he pressed into Kaiba ever so slowly. He closed his eyes at the sensation and bit his lower lip. Going slow felt even better than the first time. When he was fully sheathed, he opened his eyes and found Kaiba with his eyes closed, his mouth slightly open, and definitely blushing. _Oh, that’s hot._

He was completely still for a moment, until he couldn’t contain himself anymore and began fucking Kaiba. 

It wasn’t as hard and fast as last time, but vastly more enjoyable as Jounouchi’s mind wasn’t as far gone into the rut this time. Though the thrusts were just hard enough that he couldn’t help but groaning slightly, and he could hear that Kaiba in turn panted loudly. 

He kept going like that for a long while, feeling his restraint slip away as he fucked Kaiba harder and harder. Somewhere along the way even Kaiba began letting out small gasps and barely audible moans. Well, seems like Jounouchi wasn’t the only one enjoying himself. 

And suddenly another urge arose in Jounouchi. He wanted nothing more than to knot Kaiba. 

“Kaiba, Kaibaa~” Jounouchi went completely still and couldn’t help looking at Kaiba, who in turn looked back confused as to why he had stopped. 

“... _What?_ ” 

“I need to- I need to knot. Right now!” Jounouchi begged, and he didn’t care that he sounded like he was desperately pleading, because he was. 

“... Do it slowly. Carefully in and out” he answered after way too long in Jounouchi’s opinion. 

“Alright, alright” 

Jounouchi felt as if he was on fire, his entire body felt hot. He especially felt feverish around his face. He looked down between them to see where they were joined together, and _fuck_ that looked good. He carefully pressed his knot in and out, little by little. In and out, in and out. Jounouchi looked at his knot slightly disappear and reappear as if in trance. Above him he registered that Kaiba still had his eyes closed and mouth open with a distinctive ‘oh’ shape. 

And finally, the knot went in, and it immediately swelled up, trapping each other together for at least twenty minutes. 

___ 

The difference was like night and day. Last time the knot was unbearably painful, but this time it was downright pleasurable and entirely satisfying to feel that he was being filled completely. 

Jounouchi was laying on him, with his face buried in the crook of Seto’s neck. It all just felt so _good,_ the knot, the feeling of the other boy’s body weight on him... The smell of alpha in rut. He let himself just feel it for a couple of minutes, and tried not to think of anything. 

Jounouchi sighed deeply, he also sounded quite satisfied. “So” he started. “What’s going to happen next, I mean, after we’re done with the knotting?” 

“I’m going to be in heat for at least another twenty hours. I’m guessing we’re going to have couple of more rounds of sex and knotting.” 

Jounouchi just gave him a big, stupid, but sincere grin “Well, that’s alright with me!” 

**Notes for the Chapter:**

> I realize now that I may have accidentally given some readers the impression that there's going to be mpreg in this story. If you were looking for that then I'm sorry, I'm not planning to include any pregnancies in the story. :P
> 
> I included the talk of pregnancy during chapter 1, since I thought that it is a natural fear when two people have unprotected sex. 
> 
> Otherwise I hope you enjoyed this chapter! And I'm always open to constructive criticism ~


	3. Kaiba's identity

**Summary for the Chapter:**

> Kaiba comes to grip with his new identity

**Notes for the Chapter:**

> This was a really hard chapter to write since it's sandwiched in between chapter 2, where plot conveniences happened to have Kaiba and Jounouchi continue having sex, and the next chapter where we enter Battle City!

I'm an omega

The words hung in the air like a thick blanket. For several moments neither Seto nor Mokuba said anything. 

_“You_? How can _you_ be an omega? _”_

“I’ve asked myself the same question.” 

“This doesn’t make any sense!” 

Seto knew that Mokuba had suspected that something was up, that Seto had been acting differently lately, and that it wasn’t just because of the events with Kaiba Corp or Duelist Kingdom. Mokuba had asked about Seto’s behavior of course, and each time Seto had told him ‘I’ll tell you, but not now’. Mokuba hadn’t pried or attempted to dig deeper, and Seto was endlessly albeit silently proud that he had the best little brother. Now was the time, though. 

It had been around a month and a half since the presentation, and Seto had had time to wrap his head around his new identity and how that would affect his public and personal life. Also, he had needed time to adjust to his mating situation with Jounouchi. 

They were currently situated at the Kaiba mansion on a rare day off. Mokuba gave him a concerned and thoughtful look. 

“When did it happen, Seto?” 

Seto mentally steeled himself as he began to tell his brother about the encounter with Yuugi and his gang of friends on Duelist Kingdom. How he had dueled Jounouchi and won supremely and completely destroyed the mutt. Perhaps going into detail about the duel wasn’t strictly necessary, but still. This was when it became more difficult to tell the story, but Seto did it anyway. He told Mokuba about the sudden heat, and that Jounouchi happened to be there at the wrong time, and that he also happened to be an alpha. 

Seto paused, as he assessed Mokuba’s expression. His little brother looked like he wanted to say something, but didn’t. 

Without going into any detail, Seto continued talking. He told in the most clinical way possible, that yes, he and Jounouchi had mated, and because of the circumstances of the first heat, they had to continue mating in the foreseeable future. 

“... Wow. That was not what I expected.” 

“I hope you understand why I waited to tell you, Mokuba.” Telling his brother the unadulterated truth was a tough pill to swallow, but he thought that Mokuba deserved to hear it. 

“Of course, big brother!” Mokuba gave him another thoughtful look. “How do you feel about all of this. About being an omega?” 

The question took Seto slightly aback. He honestly hadn’t thought about how it made him _feel_. He had spent more mental energy on how his public perception would change once he revealed himself and how he should spin the media. While the society at large had come a long way with treating omegas as equals to betas and alphas, it still wasn’t perfect. He knew that his presentation would affect the corporate dynamics in an unfavorable way. While no one would admit it out loud, he knew, that alphas were simply just preferred in positions of power, and his position as CEO would be greatly scrutinized from now on in a way that it had never been before. Everything he would do after the outing would be perceived through omega-lenses. 

But how did it make him _feel_? Huh. 

“I don’t know, I haven’t thought about it.” 

“Hmm, knowing you, you probably haven’t” 

Now what was that supposed to mean? 

___ 

Jounouchi was currently sitting in the back-seat of an overly fancy car with what he assumed was one of Kaiba’s private chauffeurs. He was currently being driven to the Kaiba mansion for some more booty-action. Jounouchi couldn’t help snickering to himself at his internal quip. He didn’t care if he seemed weird to the chauffeur who was sending confused looks through the rearview mirror. 

The summer day was pretty mediocre all in all, but it became much better ever since he got the call from Kaiba. Another heat was underway. He couldn’t help being giddy at the thought. Soon enough the car reached the mansion, and Jounouchi got out. 

On the way to the stupidly, impressive building he had to try to contain himself. He recalled Kaiba’s heat that had occurred just a month prior. Man, these heats were frequent, but as Kaiba had said, an omega’s first couple of heats could be unpredictable. Helping Kaiba through his heats weren’t all fun and games, after all... Even if they were. Just a smidge. The previous session had been extremely satisfying. Even if it had become a chore towards the end. 

The last heat had lasted about twenty-nine hours in total, though Jounouchi had ‘only’ been present for twenty-five of them. Before his first time with Kaiba, Jounouchi had masturbated an extensive amount to the fantasy of helping an omega through their heat, though he had to admit, the experience with Kaiba had been a lot different. First of all, the heat came in waves, which surprised him. It wasn’t just constantly having sex. But now that he thought about it, having constant sex for twenty-four hours straight sounded pretty unrealistic. He supposed. 

The heat had been considerably milder than anticipated in the beginning. Both boys were able to talk to each other about it, proceed with relative caution, and still be _themselves_. After the first knotting, both boys calmed down. After about thirty minutes, Kaiba’s heat flared up again, which in turn had Jounouchi go into another rut, and they were once again at it. 

This cycle of knotting, calming down, Kaiba’s heat flaring up, repeated throughout the twenty-nine hours, though Kaiba’s heat reached its peak around the tenth hour. It had been so intense, that it sent Jounouchi into an equally intense rut; he could barely remember what had happened during those few hours. After the peak, the heat began to wind down, which enabled both boys to catch a few hours of sleep, until Kaiba woke him to have more sex. 

The sex at the dead of night were pretty rough, as little Jou had been quite sensitive and used at that point. But now little Jou had recuperated, and was ready for another round. 

A maid opened the front door for Jounouchi and entered into the lobby area. Because, of course a ridiculously huge mansion like this one had a lobby area. He turned to the maid “Uhh, should I just go up to his room like last time?” The maid nodded. He proceeded down the hallway to Kaiba’s bedroom and knocked before going in. This time Kaiba was sitting on the bed, reading a book while waiting. 

“Took you long enough” Kaiba said, setting the book aside. 

“Aww, impatient for me?” 

“You wish, loser.” 

It was nice to have some back and forth banter as the idea of approaching the other boy to have sex was still pretty nerve-wracking. As he got closer, the smell of heat became stronger, and Jounouchi felt little Jou stir. Kaiba began taking off his clothes unceremoniously, and Jounouhi followed suit. _I guess he’s a lot less shy this time._ Soon they both found themselves on the bed, this time both were completely naked. 

“Should I _prepare_ you, again?” 

“Yes.” 

“Could you at least say ‘please’?” 

“... No” 

Having sex proceeded much like last time. Kaiba laid on his back while Jounouchi opened him up with his fingers as the hole was being surprisingly tight, once again. The sex itself was quite good, although they quickly went on to the knotting. Jounouchi had to concentrate and muster up all of the restraint he had to not just shove it in there. He eased the knot in little by little, until both boys were stuck together. Jounouchi could get used to this. Being knotted felt just as satisfying as it had the previous times. Both boys laid there, not saying anything, and just enjoyed the sensation. Kaiba closed his eyes, looking completely relax and content in the moment. When the knot deflated and released them, Kaiba opted to lay on his back, presumably to wait for the next wave of heat. Jounouchi had other plans. With a grin on his face he went and got his green jacket which lied on the floor. 

“Hey Kaiba?” 

Kaiba didn’t answer and instead looked at him with an indifferent expression. 

Jounouchi produced his deck from the jacket. “Want a rematch?” And sure enough, soon both boys found themselves sitting on the bed playing Duel Monsters. “I’ve been waiting for a rematch ever since Duelist Kingdom, you know!” Jounouchi said, completely engrossed in the game. 

“This won’t be much of a duel at all” Kaiba mocked. “The other duelists must have been awfully pathetic, if someone like you ended up as one of the finalists.” At that moment, Kaiba had managed to summon his Blue Eyes White Dragon. Shit. 

“Hey! I _earned_ my spot as one of the finalists!” 

Kaiba just gave him a derisive snort. “Oh please, you would never have come nearly as close if it wasn’t for Yuugi. You didn’t _earn_ anything of your own.” And just as he said that, his Blue Eyes White Dragon wiped out Jounouchi’s Flame Swordsman. 

This was turning out just as bad as the first duel. And just as humiliating. Kaiba sure didn’t hold anything back when it came to either crushing his opponent or spewing condescending comments. 

“Hmph, I had kinda expected that you would be just a _little_ nicer to me this time around.” Jounouchi said with a scowl on his face. 

“Really, is that so?” Kaiba didn’t even try to hide the mocking tone in his voice. 

_That_ touched a nerve and Jounouchi got up with an angry expression on his face. “I didn’t have to do any of this, you know! I’m only here because _you_ asked me, so you don’t get those complications!” 

Kaiba in turn gave a derogatory snort which infuriated him even further. “Don’t flatter yourself, you’re only here because you have an easy and free opportunity to knot an omega.” 

“I- uh-” Jounouchi really didn’t have anything to respond to that. “Whatever!” He yelled, maybe a bit too loudly, as he focused his attention on the game, that he was losing quite fantastically. Again. That prick. 

___ 

It didn’t take long until Jounouchi faced his crushing defeat, and the blond boy silently put away his deck while Seto verbally humiliated him just for good measure. Now _this_ was turning out to be quite a nice heat. 

Jounouchi sent him a dirty look. “How come someone like _you_ ended up as an omega? You’re not like any omega _I’ve_ ever met.” 

Seto didn’t show it, but that remark cut him deeply. Of all people, how come Kaiba Seto had turned out as an omega? On an intellectual level he knew everyone was different and that while alphas, betas, and omegas usually had personality traits prescribed to each, not all inherited those traits. Though Seto had to admit, that the stereotypes were deeply ingrained in him, as he only imaged alphas as being dominant, assertive leaders and omegas as being subdued, nurturing, and wanting a lot of pups, while betas were mellow and down to earth and completely unassuming. 

Seto certainly didn’t see himself fit into that omega mold. Not now, and absolutely not ever. Before his first heat he had never imagined himself as nurturing, wanting any pups, or being the passive recipient of sex. That train of thought just didn’t sit well with him. Not at all. 

And just as he had finished his thought the heat flared up again, and much stronger this time. He felt that telltale feeling of a fresh wave of slick move out from his behind. “Jounouchi” he breathed. 

Jounouchi was on him almost instantly, already reacting on the heat. The blond boy had pressed Seto down on his back, as Jounouchi began to kiss him sloppily on the jaw and gave him a trail of kisses down to the neck. Seto closed his eyes and allowed himself to enjoy it for just a moment before he grabbed Jounouchi’s shoulder and pushed back until the other boy laid on his back, reversing their positions. Jounouchi looked at him with wide eyes, clearly not expecting this turn of events. 

Now Seto was the one to kiss Jounouchi one the neck while he reached behind him to grab Jounouchi’s already leaking member. Seto sat up on his knees and guided it to the entrance. Beneath him Jounouchi was looking up at him in confusion and amazement. Seto closed his eyes, bit his lower lip and waited. He could feel that Jounouchi began to tremble in anticipation. 

“Oh, Kaiba-Kaiba pleease~” 

And Seto didn’t wait a moment longer as he slowly lowered himself on Jounouchi’s eager member. The stretch that it provided was just delicious. Despite have being knotted quite of couple of times already, the size of the other boy’s regular sized penis still felt completely satisfying. Especially now that Seto’s hole was sensitive from the previous mating. Soon enough it was fully sheathed, and Seto didn’t wait before bending over Jounouchi for purchase and moved up and down, creating a nice friction. The pace wasn’t slow either, and Seto got a good exercise out of it. 

The last couple of times, Seto had tried his damndest to not utter any sound, though it always seemed futile when the heat reached its peak and he was only a shadow of himself as the sex-crazed, animalistic part of himself took over. This time Seto’s embarrassment over the situation could go fuck itself. He felt good, this feels amazing, and Kaiba Seto doesn’t suppress himself. Ever. 

“Oh, aah~” Seto moaned at the sensation of a good mating. The fact that he was more sensitive from the previous mating made it all the more pleasurable. 

Seto looked down just in time to see Jounouchi’s reaction, as he shot a completely bewildered look at Seto’s newfound vocalism. He couldn’t help smirking at Jounouchi’s goofy facial expression. Seto kept moving himself up and down, and as he penetrated himself on Jounouchi his moans grew louder and lewder. 

“Oh, Kaiba~” Jounouchi grabbed hold of Seto’s shoulders. “Raise your ass a little” Surprisingly Seto found himself complying with the request. “Yeah, just like that.” Still laying on his back with Seto on top of him, Jounouchi bent his legs and his feet found purchase on the bed before he began fucking Seto in a hard and furious pace. _Slap, slap, slap._

Seto’s moans and gasps where short and cut off at the pounding. The sensations left his mind completely blank. In the heat of the moment and pleasure, Seto took the opportunity to give Jounouchi a mating bite of his own, right where the the shoulder meets the neck. Jounouchi just grunted in reply. 

They continued pounding away like that for a while, until Seto felt another urge rise. With his hips, Seto pressed Jounouchi down into the mattress and successfully stopped him from mating. The alpha seemed to want to protest, until Seto began pressing further down. Rather than easing the knot in little by little, Seto kept pressing downwards without relenting, until the knot was fully inside. 

“Oooh” Seto didn’t care to contain his sounds of pleasure, as he felt the knot expand. It filled him up and it tingled in the best way around his ring muscle. Now that is pleasure. Seto had to admit that the sensation of the knot expanding inside of him was his favorite feeling in the mating process. 

Both boys laid still and just panted for a while. 

“Wow” was all Jounouchi could say. 

_Wow indeed._

It was the next day, the heat was over, and Jounouchi was long gone. Seto had made sure that he was sent home by car. Seto may have been tired, but it was only the early afternoon and he might as well go to Kaiba Corp and see if he had missed anything while he was in heat. 

He had thought about it, and being an omega wasn’t as bad as he had initially thought it would be. Somewhere back in his mind he thought that being an omega, being the one who was ‘penetrated’, would somehow be degrading. But it wasn’t. Instead the experience was had been pleasurable and satisfying in a way he had never imagined. In his quiet mind, Seto acknowledged that presenting as an omega had enriched his perceptions of the world in a way he hadn’t expected. 

He had thought that presenting as an omega would hurt him and his reputation, but he quickly realized that it would only hurt him if he let it. Others would only think less of him if he also thought less of himself. And he was never going to let them get the opportunity. 

Seto didn’t have to prove anything to others than himself, but he was going to show the world that he was the best, and that no one on this earth can even get close to reaching Kaiba Seto. And he knew the perfect way to demonstrate that to the world. 

**Notes for the Chapter:**

> Thanks to Sunflowereevee for inspiring Kaiba and Jounouchi playing Duel Monsters while waiting for the next wave of heat!


	4. The Alpha's Voice

Jounouchi was beyond livid. Not only had  Kaiba arranged another Duel Monsters Championship without at all mentioning it to him the last time they saw each other, but Kaiba had purposefully not invited  _ him _ to attend! He had even managed to become the fourth runner up during Duelist Kingdom. What gives?

Jounouchi didn’t know what made him angrier, the lies or simply not inviting him to the tournament and thus not acknowledging him as a worthy duelist. He had even mated the guy!  Jounouchi had long decided that he wanted to give  Kaiba a piece of his mind when the rich bastard’s next heat came up.

Of course,  Kaiba had to announce the Battle City Tournament in the most awesome, ridiculous, over-the-top way possible by showing up in a helicopter in the middle of Domino city and announcing it to the world. That was such a Kaiba thing to do.  Jounouchi had to get his thoughts back on topic;  Kaiba was a jerk, and he needed to know it. 

As of now the tournament was in full swing, and  Jounouchi had found his own way to enter it. No thanks to Kaiba, thank you very much. After an unfortunate turn of events he had lost is Red Eyes Black Dragon, but through the tournament he had won new cards like ‘Insect Queen’ from Weevil Underwood and ‘Jinzo’ from Espa Roba, which were pretty sweet. All in all, he was quite proud of the outcomes of these duels, and after each win he felt more and more confident that he might win over Kaiba one day. Then he might get invited in future tournaments! Not that he  _ cared _ , or anything.

It was actually the same evening that he had defeated Weevil that he got the call from  Kaiba . That was perfect timing. He had just gotten a boost of self confidence in his dueling skills from the match, and he was ready to shove it in  Kaiba’s smug face.

___

It was quite unfortunate timing, Seto was crushing his opponents in the tournament when the first signs of heat began to appear. He wrapped up a rather pathetic excuse of a duel with Obelisk the Tormentor which sent the other duelist flying. Soon enough he found himself in the backseat of a car home accompanied with Mokuba besides him.

“I guess this means that we’re having a break for a day or two, huh?” Mokuba asked.

“Yes” came  Seto’s terse reply. He was already finding himself squirming in the seat, a few trickles of slick escaping his backside. He knew that  Mokuba knew about him being an omega and the heats, but this was the first time that his little brother was actually going to witness him going through one. It was of course inevitable that  Mokuba would at one point or another experience  Seto’s heat; smell the smell and watch as his brother’s behavior gradually become more animalistic. Though it didn’t make  Seto less uncomfortable about the situation. For once, he wished that  Mokuba wasn’t there.

Seto tensed slightly when  Mokuba leaned in and gave him a small whiff before returning to his seat.  Seto didn’t say anything as it was a given that his brother would be curious about the situation and wanting to know how a heat smelled like, even if it was just in the early stages.

“So, uh-”  Mokuba began but quickly stopped himself. He looked out the window turned away from Seto. He looked conflicted.

As quietly as he could,  Seto took a deep breath. He was sure that whatever  Mokuba wanted to know, it was going to be of a private and embarrassing nature. “Go head  Mokuba , ask what you want to ask.”

“Are you going to call  Jounouchi when we get home?”  Mokuba tentatively faced his brother again.

“I am.”

Mokuba looked down and appeared as if he was in deep contemplation. He twiddled his thumbs slightly. “Then, are you two going to-” he looked at  Seto with big curious eyes “you know?”

“We are.”  Seto shifted slightly, he told himself it was because of the heat.

Mokuba looked more innocent than he had in years. While  Seto didn’t exactly  _ want _ to have this conversation or answer as honestly as he did, he thought it was a necessary to talk freely with his brother about it. He wanted to show him that the topic wasn’t taboo, and whatever that was happening between him and Jounouchi was natural. Or, as natural as it could be under the circumstances. 

“Is he going to knot you?” 

Seto couldn’t help clearing his throat at the blunt question. This time  Mokuba just stared curiously without looking away.  Seto felt his face heat up from his neck to his cheeks and hoped that he wasn’t blushing. With hesitation he finally answered a low “Yes.”

Without saying anything Mokuba returned to his seat and looked straight ahead, thinking. “Does it hurt?”

Seto couldn’t help smiling slightly “No, it doesn’t hurt. Not at all.”

Mokuba blushed a little at his own question, and he  contined twiddling his thumbs. “I’m glad.” He said with a small voice.

The car ride resumed in silence after that.  Seto could sense that  Mokuba was still curious about the subject and his relationship between him and  Jounouchi and wanted to ask more questions.  Seto contemplated whether he should encourage  Mokuba to enquire further, or if the conversation had already reached proper amounts of awkwardness.  Mokuba decided for him when he asked.

“Do you even like  Jounouchi ?”

Seto wasn’t able to answer right away.  Seto recognized that he would never have chosen  Jounouchi for mate, and the only reason that they were mates now were because of unforeseen circumstances. It was a necessary evil, so to speak. Once the one year was up, he would no longer be seeing Jounouchi. 

But whether he actually liked  Jounouchi ? And in what regard, exactly.  Jounouchi’s personality? Certainly not,  Seto found the blonde duelist-wannabe to be insufferable whenever he opened his mouth. Though he had to admit,  Jounouchi was more than adequate for the mating itself, even though  Seto had no other points of reference. Mating with  Jounouchi was pleasant and pleasurable, if nothing else.

“I don’t know,  Mokuba .”

Seto sat on his bed once again reading a book, or at least trying to. It grew increasingly more difficult to concentrate on the text as he felt more slick escape, and his thoughts wandered into less innocent places. Nonetheless he tried to distract himself while waiting for  Jounouchi who could arrive at any moment.

Well, speak of the devil. At just that moment he heard loud footsteps stomp closer and closer to his bedroom, and with a muffled voice he heard  Jounouchi yell at the other side of the door “You bastard!”

BANG! The door sprang open as  Jounouchi kicked it. That was rather unnecessary,  Seto thought, as the door was unlocked. Other than that, he didn’t outwardly react to the blonde boy’s dramatic and violent entrance. 

“You bastard!”  Jounouchi pointed aggressively at  Seto . “You didn’t invite me to your  stinkin ’ tournament!”

Seto mustered all of his willpower not to laugh in the other’s face. Because, oh right, he hadn’t invited that  second-rate duelist to the tournament.  Seto put the book aside and calmly stood up. “ Of course I haven’t invited a loser like you to  _ my _ tournament. Why would I?”

“ Grrrr ! Because I ranked fourth on Duelist Kingdom! Or did you completely forget that?”

“ Hmmph . A ranking you don’t deserve, I’m sure, based on my first duel with you.”  Seto retorted with a mocking tone. “Face it, mutt, the only reason you ever got as far as you did was because of  Yuugi , because he felt charitable.”

Jounouchi’s eyes flashed with anger and his face contorted into a snarl, it was practically animalistic in nature. With a low growl that didn’t at all sound like  Jounouchi's voice, he said  _ “Kaiba.” _

Seto felt his back go stiff as a board as all of the hairs on his body stood on end. With wide eyes he tipped back his head and exposed his neck, a clear sign of submission.

For just a moment the entire world stood still, and neither said anything.

It was something primal underlying in his brain that compelled him to obey the alpha. He couldn’t see  Jounouchi’s expression as he refused to look at the other boy in his submissive position, instead opting for looking at the ceiling.  Seto’s entire body trembled. It wasn’t quite fear, but something close to it.

“ Kaiba . Please stop.”  Jounouchi said with a small voice, he sounded young and boyish.

And just like that,  Seto’s body obeyed him again and he could look down.  Jounouchi just stared at him, completely bewildered, his eyes creased with worry and confusion. Seto could only look back with what he assumed was a similar expression on his face. With embarrassment he realized that he still visibly trembled. In front of Jounouchi.

The contrast between the argument that had just occurred and the current, tense mood was so sudden that it actually felt quite violent. The shift in tone felt like a whiplash, and  Seto couldn’t quite comprehend what had just happened.

That was the  _ alpha voice. _ And  Seto had just instinctively submitted to it.

___

“I-I’m sorry,  Kaiba . I didn’t realize that I could-… If I knew, I would never have-” but the words died on his lips.  Jounouchi was at a completely loss for words.

On an intellectual level he knew that an alpha had power over the omega that they were mated with. It was an animalistic part of them that still prevailed in their biology. It was just that Jounouchi had never even considered that he could ever have such a hold on Kaiba. Kaiba Seto just seemed so above everything, so untouchable. Somehow Jounouchi had kind of assumed that, of course, it wasn’t possible for _any_ alpha to command him in that way. 

But it  _ was  _ possible _. _ And he had just proved it.

Jounouchi vaguely thought that he should probably be smug about it, that he should shove it in the other boy’s face that he could hold this kind of power over him. That when it came down to it, Kaiba was like any other mated omega. But instead he just felt nauseous. The idea that he could bend another human being against his will like this made him sick to the stomach.

While  Jounouchi was wrapped up in his inner turmoil,  Kaiba had seemed to calm himself down and had stopped trembling. He cleared his throat “Right. We should probably move things along”

Just as  Kaiba was turning around to face the bed,  Jounouchi stopped him “Wait! We should talk about this.”

“Why?”  Kaiba turned back around with an unreadable expression. “I assume that you won’t do this again?”

“... Yes, but-”

“Then what is there to talk about?”

In all of his dealings with  Kaiba ,  Jounouchi had never felt this vulnerable before. He couldn’t at all make himself go and mate with  Kaiba , not right after something like this. Despite himself,  Jounouchi felt himself tremble, just like  Kaiba had done a few moments earlier. 

“How can you be so calm about this?”  Jounouchi asked with a small voice. 

“Well. It was just an accident, wasn’t it?”  Kaiba said with a level voice. “I’m guessing that you have never used that voice before.”

“Yes, it was. An accident, I mean. And no, I have never used that voice before.”  Jounouchi bit his lip, looking away. “I’m sorry.”

“Then, what is the problem?”

“Well- because it just  _ is  _ a problem? I just used the  _ alpha voice _ on you!”

Kaiba just looked at him, still with an indecipherable  expression. ”This really bothers you, doesn’t it?”

“Of course, it does!”  Jounouchi exclaimed, suddenly slightly hysterical. “I mean, I just... Used that alpha voice to  _ command _ you! And, and-”  Jounouchi continued to blabber, still trembling slightly, and ran his fingers nervously through his hair. He couldn’t seem to stop his mouth from spewing absolute nonsense. He went over the same thing over and over again, like a broken record, while  Kaiba just looked at him.

Suddnely, Kaiba placed a tender hand on his shoulder. Jounouchi immediately stopped talking, and looked  Kaiba in the eyes. The other boy regarded him with a level expression. “It’s alright,  Jounouchi . It was just an accident.”

They looked each other in the eyes for a moment, before  Kaiba retreated his hand. 

“So, you’re not angry?”  Jounouochi cringed inwardly at how soft his voice sounded, but he couldn’t help it.

Kaiba took a deep breath. “Since it seems like you need to know, then let me phrase it like this; I’m sincerely not bothered. I know that you didn’t do it consciously.”

Jounouchi didn’t know how to respond, and just stood gingerly on the spot.

“Alright.”  Jounouchi exhaled sharply and tried to relax the tension in his shoulders and nodded, though mostly to himself. “Alright.”

Suddenly, standing here to mate with Kaiba was just as painfully awkward as the first time he stood in his bedroom. After his accidental display of power, he didn’t know if it was okay to proceed. He didn’t know if he even wanted to proceed.

“Well?”  Kaiba asked expectantly. He had already shed his black turtleneck and was naked from the waist up. 

“I don’t know if I can do it now”  Jounouchi answered lamely, watching the floor.

Jounouchi could feel  Kaiba’s eyes on him for a moment, until the other boy said “Maybe this will help.” And then  Kaiba did something  Jounouchi would never have imagined that he would do.  Kaiba hugged him with both hands behind  Jounouchi’s head, pushing his face into  Kaiba’s neck. “Now take a deep breath.”

It took a few seconds for  Jounouchi to register  Kaiba’s words as he was completely dumbfounded at the sudden intimacy. Then he did as he was told and took a deep breath, and man, if that didn’t help. He inhaled  Kaiba’s heat, and little Jou sprang to life. All of the stress and tension melted away as the newfound arousal took its place instead and he reciprocated the hug, inhaling once again.

Everything went easier from there as  Jounouchi undressed and got into bed with  Kaiba , their movements languid and smooth.  Jounouchi did the usual of preparing  Kaiba with his fingers before proceeding with the mating that eventually ended with the knot, trapping them together.

Both boys laid on their sides while knotted. Just lying there on the warm and soft bed was extremely cozy, and  Kaiba was currently the embodiment of relaxation as he lied there with closed eyes, seemingly just enjoying the experience. Now that Jounouchi had a moment to slow down and think again, a pang of shame washed over him. He knew that  Kaiba had said that he wasn’t bothered, but that didn’t mean that  Jounouchi had gotten over the... alpha thing. 

“Are you sure that you’re not angry?” he asked tentatively.

“I’m sure.” The other boy answered without opening his eyes.

Jounouchi didn’t say anything further. Instead he just watched Kaiba. He actually looked perfectly peaceful. It was completely unlike all of the other times he had seen him on Duelist Kingdom, in the Battle City tournament, and on tv. It almost felt like he was imposing on a private moment.

A thought occurred to Jounouchi.

“Do you hate me for any of this?”

Kaiba opened his eyes and looked like he was about to say something.

“I mean! Not for the thing that  _ just _ happened, but for all of this. The whole mating thing that happened on Duelist Kingdom?”

Kaiba seemed to contemplate the question briefly before answering “No.”

“... No? Really?” Jounouchi said in disbelief.

“I suppose I just didn’t think about it that way” he seemed to be in deep thought as he answered. “I never thought as this as being anyone’s fault, per se... We both just happened to be at the wrong place at the wrong time. So no, I don’t resent you for this.”

Jounouchi was slightly stunned. That was a surprisingly mature and sincere answer, and he had no idea how to respond to that. A knot in the stomach that he didn’t know he had loosened.

Their easy relaxation resumed. Until-

“How come you didn’t invite me to your tournament!?”

Kaiba sighed in annoyance “Not this again.”

___

Seto was jostled awake from his slumber. He was sleeping with his back turned to  Jounouchi when said boy had begun to push him on his stomach in an effort to mount him from behind. With a groggy groan  Seto looked at the clock on the bedside table which showed it was 10.57 before noon. They had been at it the entire night because of the heat and as a result they only managed to fall asleep at six o’clock in the early hours in the morning. This would completely fuck with his sleep schedule, again. Still sleepy, he let Jounouchi push and manipulate his body as he vaguely realized that  Jounouchi was in a rut as a result of  Seto’s heat flaring up again in his sleep.

He felt two fingers enter his tender backside. Several rounds of heat, sex, and knotting tended to make his hole sensitive to the touch. He grimaced slightly at the memory of previous heats where  Seto had been incredibly sore at the end of it, which made the mating quite painful. This wasn’t going to be any different. 

Jounouchi entered a third digit, and even that hurt a little. “Mmm, Jounouchi” Seto whimpered, too exhausted to care about how he sounded.

“Shh, I’ll be as gentle as I can be”

Soon enough the fingers were removed and was replaced with  Jounouchi’s member. It slipped easily in as Seto was quite slick and loose at this point, but he still couldn’t manage to suppress a slight hiss. He buried his face in his pillow and grabbed the sheets as he mentally prepared himself for the impending mating.

Jounouchi was now fully sheathed inside and set a leisurely pace as  Seto laid flat on his stomach. As they mated the soreness didn’t feel as bad. It was mostly when  Jounouchi entered, and his hole had to readjust to the intrusion once more. Hell, the tenderness and soreness even heightened the sensations and made the whole experience both slightly painful and therefore immensely pleasurable. This made  Seto both moan and whimper.

Before long  Jounouchi set a more frantic and what felt like a punishing rhythm, which made the mating more pain than pleasure. 

“ Jounouchi-hnng ”  Seto grimaced, now biting the pillow.

“Just- give me a moment”

The sounds of  Seto’s increasingly louder whimpers and  Jounouchi’s groans filled the room. And finally,  Jounouchi stopped. His member was buried down to the base, where his knot was. He slowly though unrelentingly pressed it in. Soon enough it was inside and swelled up  immediately at which  Seto failed to suppress another loud hiss.

Now knotted,  Seto and  Jounouchi was fully awake, yet still tired. Normally, knotting felt quite pleasurable and satisfying, but right now it just throbbed with a dull ache. At least it wasn’t as bad as his first knotting in the woods. Though it was kind of nice feeling  Jounouchi’s weight on top of him, as  Jounouchi had knotted him from behind, even if he could feel his ring-muscle twitch with each heartbeat around  Jounouchi’s cock.

“You sore, Kaiba?”

“What do  _ you _ think?”

“If it makes you feel any better, Little Jou is pretty sore too right now”

“... Little Jou?”  Seto answered with a mocking tone. 

“Yeah! That’s what I call my-”

“Yes, thank you! I  _ know _ what you’re referring to.”

Jounouchi had the gall to laugh at that. “I’m just saying, you’re not the only one right now” he continued with a chipper voice.

“You know, mutt?”

“Huh?”

“I lied. I actually  _ do _ resent you for all of this.”

For a moment  Jounouchi didn’t respond.  Seto could just imagine his stupid facial expression as he tried to wrap his head around the words.

“ Heey , was that a joke?”

“I guess the world will never know”  Seto replied easily.

Jounouchi just laughed a goofy laugh that  Seto had somehow come to like as of late. It made the mating sessions more pleasant. Not that he would say that out loud or anything.

Their conversation died down, and they just waited out the knot in silence. Now fully awake, Seto was left contemplating. Specifically, on the events that occurred yesterday.  Jounouchi had actually seemed more upset at the alpha voice than  Seto had, which had caught him by surprise. If anything,  Seto should be the one to be upset, to be wary of the implications. He was the one who could be controlled to some extend by the alpha, after all. And yet,  Seto wasn’t at all as scared or bothered as he should have been.

This was a major reason that an omega should be careful of who they chose to mate with. Especially if it was with an alpha. You could just never know if the alpha would turn around and abuse that power of the omega afterwards. In fact,  Seto could recall several domestic abuse cases where the alpha had mistreated and controlled the omega with that specific alpha influence. The thought made  Seto shudder slightly. 

He perhaps  _ should _ be more shaken by earlier events with  Jounouchi , and they perhaps  _ should _ talk about the implications at length. What if  Jounouchi lost his temper in a public setting? What if they found each other in another duel and  Jounouchi used his alpha voice in the middle of it? Intellectually speaking, these were very real and valid concerns.

But somehow  Seto wasn’t nervous at all. Because he trusted Jounouchi.

“ Uughh ”  Seto grounded out at the realization.

“What is it, Kaiba?”

“Nothing,  _ mutt _ ”

**Notes for the Chapter:**

> In hindsight I should probably have come up with a cooler name than 'alpha voice' but eh.
> 
> Still, this was a really fun chapter to write, and I really like it!

**Author's Note:**

> Please comment! I'll take both praise and constructive criticism! And a kudo wouldn't hurt either. I hope you enjoyed! :D


End file.
